LED-based lighting unit with optical component for mixing light output from a plurality of LEDs

Abstract

Methods and apparatus related to an LED-based lighting unit ( 10, 110 ) having an optical component for mixing light output from a plurality of LEDs ( 34, 134 ). In some embodiments the optical component may include at least one reflective surface interiorly thereof and the LEDs ( 34, 134 ) may be vertically arranged about the reflective surface. At least some of the LEDs ( 34, 34 ) may generate a light output generally directed toward the reflective surface. The reflective surface may be configured to direct at least some of the light output directly incident thereon through a light output opening ( 25, 125 ) of the optical component.

What is claimed is: 
     
       1. An LED-based lighting unit, comprising:
 a longitudinally extending lighting unit axis; 
 a light output opening surrounding said lighting unit axis; 
 a reflector positioned above said light output opening and surrounding said lighting unit axis; 
 a plurality of LEDs positioned below said light output opening and surrounding said lighting unit axis, each of said LEDs emitting a light output having a light output central axis generally directed toward and perpendicular to said lighting unit axis; 
 at least one reflective surface interposed between at least some of said LEDs and said lighting unit axis; 
 wherein said reflective surface is positioned such that a plurality of said light output central axis are directly incident thereon; and 
 wherein said reflective surface is configured such that a plurality of said light output central axis directly incident thereon are directed through said light output opening. 
 
     
     
       2. The LED-based lighting unit of  claim 1 , wherein said reflective surface is a reflective conical optical member having an apex most closely adjacent said light output opening. 
     
     
       3. The LED-based lighting unit of  claim 2 , wherein said apex is centered on said lighting unit axis. 
     
     
       4. The LED-based lighting unit of  claim 1 , wherein said reflective surface includes a plurality of planar surfaces converging toward an apex. 
     
     
       5. The LED-based lighting unit of  claim 4 , wherein said apex is centered on said lighting unit axis. 
     
     
       6. The LED-based lighting unit of  claim 1 , wherein said LEDs are arranged on a plurality of planar mounting surfaces centered about said lighting unit axis. 
     
     
       7. The LED-based lighting unit of  claim 1 , wherein said reflective surface includes a plurality of pyramidal structures radially arranged about said lighting unit axis and each having an apex most closely adjacent said lighting unit axis. 
     
     
       8. An LED-based lighting unit, comprising:
 a longitudinally extending lighting unit axis; 
 a light output opening surrounding said lighting unit axis; 
 a light altering structure positioned above said light output opening and centered about said lighting unit axis; 
 a plurality of LED PCBs positioned below said light output opening and surrounding said lighting unit axis, each of said LED PCBs being substantially parallel to said lighting unit axis and having interiorly facing LEDs thereon emitting a light output having a light output central axis; and 
 a reflective conical optical member provided interiorly of said LED PCBs and centered about said lighting unit axis, said conical optical member having a base and an apex, said apex being more proximal said light output opening than said base. 
 
     
     
       9. The LED-based lighting unit of  claim 8 , wherein an exterior surface of said conical optical member between said base and said apex is generally concave. 
     
     
       10. The LED-based lighting unit of  claim 8 , further comprising a plurality of support structures interposed between said LED PCBs. 
     
     
       11. The LED-based lighting unit of  claim 10 , wherein at least an interior facing portion of each of said support structures is reflective. 
     
     
       12. The LED-based lighting unit of  claim 8 , wherein at least an interior facing portion of each of said LED PCBs is reflective. 
     
     
       13. The LED-based lighting unit of  claim 8 , wherein the distance along said lighting unit axis between said base and said apex is greater than the distance along said lighting unit axis between said apex and said light output opening. 
     
     
       14. The LED-based lighting unit of  claim 8 , wherein an odd number of said LED PCBs are asymmetrically arranged about said lighting unit axis. 
     
     
       15. The LED-based lighting unit of  claim 8 , wherein said light altering structure is a reflector. 
     
     
       16. An LED-based lighting unit, comprising:
 a longitudinally extending lighting unit axis; 
 a light output opening surrounding said lighting unit axis; 
 a plurality of LED PCBs positioned below said light output opening and surrounding said lighting unit axis, each of said LED PCBs being substantially parallel to said lighting unit axis and having interiorly facing LEDs thereon emitting a light output having a light output central axis; and 
 a plurality of reflective pyramidal structures provided interiorly of said LED PCBs and radially arranged about said lighting unit axis, each of said pyramidal structures having an apex most proximal said lighting unit axis and a base most distal said lighting unit axis, said base receiving a majority of said light output from a single of said LED PCBs. 
 
     
     
       17. The LED-based lighting unit of  claim 16 , wherein an odd number of said pyramidal structures are provided. 
     
     
       18. The LED-based lighting unit of  claim 16 , wherein said pyramidal structures are each non-symmetrical. 
     
     
       19. The LED-based lighting unit of  claim 16 , wherein said pyramidal structures each include an elongated rectangular base. 
     
     
       20. The LED-based lighting unit of  claim 16 , further comprising a horn-type reflector positioned above said light output opening and surrounding said lighting unit axis. 
     
     
       21. The LED-based lighting unit of  claim 18 , wherein said pyramidal structures each include a bottom surface and side surfaces with upper edges that converge downward towards an apex of the bottom surface. 
     
     
       22. The LED-based lighting unit of  claim 16 , wherein said pyramidal structures include bottom reflective surfaces that all converge towards the lighting unit axis. 
     
     
       23. The LED-based lighting unit of  claim 16 , wherein interior surfaces of the pyramidal structures are coated with silver metalized vacuum deposited coating. 
     
     
       24. The LED-based lighting unit of  claim 19 , wherein the plurality of LED PCBs are positioned within the rectangular bases towards their outermost portions.